president obama tried his hand at stand-up comedy saturday night at the annual white house correspondents' dinner, targeting not only his critics but himself, as well, entering to the sounds of rap music. ♪ >> thank you. how do you like my new entrance music? rush limbaugh warned you about this. second term, baby. i recognize that this job can take a toll on you. i understand second terms need a burst of new energy, try some new things, and then my team and i talked about it, we were willing to try anything so we borrowed one of michelle's tricks. >> oh, no. not a good look on the president of the united states. that is "early start." i'm zoraida sambolin. john berman continues our coverage live in boston with "starting point" right now. >>> good morning, everyone. i'm john berman live in boston this morning. our "starting point," a raid overnight in russia. why special forces wanted this man dead and his possible connection to one of the suspected boston bombers, tamerlan tsarnaev. plus, the u.s. and russia working furiously to piece together tamerlan's every move leading up to the mar